<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style type="text/css">
	.username{
		border: 0 none;       /*去掉边框*/
		outline-style: none;  /*去掉轮廓线*/
		background:#ccc;
		border:1px dashed green;
	}
	.username:focus{
		background:red;
	}
	.email{
		border: 0 none;
		outline-style: none;
		border-bottom: 1px dotted red;
	}
	.search{
		border: 0 none;
		
		border:1px solid #999;
		background: url("../04-案例/search.png") no-repeat right;
	}
	</style>
</head>
<body>

	<label for="username">用户名:</label><input type="text" class="username" id="username"><br><br>

	邮箱:<input type="text" class="email"><br><br>
	搜索一下:<input type="text" class="search">
</body>
</html>